Optical spectroscopy of isolated planetary mass objects in the sigma Orionis cluster

Дата и время публикации : 2001-08-15T01:37:09Z

Авторы публикации и институты :
D. Barrado-y-Navascués (Universidad Autónoma de Madrid, Madrid, Spain, Max-Planck-Institut für Astronomie, Heidelberg. Germany)
M. R. Zapatero-Osorio (California Institute of Technology, Pasadena, USA)
V. J. S. Béjar (Instituto de Astrofísica de Canarias, Tenerife, Spain)
R. Rebolo (Instituto de Astrofísica de Canarias, Tenerife, Spain, Consejo Superior de Investigaciones Científicas, CSIC, Spain)
E. L. Martín (Institute of Astronomy. University of Hawaii, Hawaii, USA)
R. Mundt (Max-Planck-Institut für Astronomie, Heidelberg. Germany)
C. A. L. Bailer-Jones (Max-Planck-Institut für Astronomie, Heidelberg. Germany)
. (Max-Planck-Institut für Astronomie, Heidelberg. Germany)

Оригинал статьи :http://arxiv.org/abs/astro-ph/0108249v1

Скачать pdf : http://arxiv.org/pdf/astro-ph/0108249v1

Ссылка на журнал-издание: Astron.Astrophys.377:L9-L13,2001
Коментарии к статье: Astronomy and Astrophysics, accepted
Первичная категория: astro-ph

Все категории : astro-ph

Краткий обзор статьи: We have obtained low resolution optical spectra of 15 isolated planetary mass objects (IPMOs) in the sigma Orionis cluster, and derived spectral types by comparison with nearby M and L dwarfs. The spectral types are in the range late M – mid L, in agreement with our expectations based on colors and magnitudes for bona fide members. Therefore, most of these objects have masses below the deuterium burning limit. About 2/3 show H(alpha) in emission at our spectral resolution. From our spectroscopic and photometric data, we infer that three IPMOs in this sample may be binaries with components of similar masses. These results confirm that the substellar mass function of the sigma Orionis cluster, in the form dN/dM, keeps rising in the planetary domain.

Category: Physics